Mark Dunn, Senior National Reporter

NDP Leader Thomas Mulcair dismissed assurances from top officials at the Canadian Security Intelligence Service (CSIS) and the Communications Security Establishment of Canada (CSEC) Canadians are not being watched, tracked and eavesdropped on.

The officials along with Prime Minister Stephen Harper's national security advisor testified at a Senate hearing Monday and dismissed a CBC report that said Canadians have been targeted in a nefarious Wi-Fi espionage exercise at airports.

Harper said the NDP allegations have been reviewed by an independent commissioner that oversees CSEC who found that an operation to collect metadata at passenger terminals fell within the law.

Liberals said the CSEC watchdog has no teeth and is on a short leash. They called for parliamentary scrutiny into covert activities.

Metadata mining was first approved by the Liberals in 2005 and uses communication networks to help identify where a transmission originates, and is not about retrieving e-mails, phone messages or text messages or photos.

"All this activity is within Canadian law. It protects Canadian privacy," said Defence Minister Rob Nicholson. CSEC falls under his purview.

"I know this organization (CSEC) is in the business of protecting Canadians from foreign terrorists, cyber hackers and kidnappers," he said.